TylerTrinh
1 mW
Does anyone know how the modify there power supplies as a charger?
Meanwell S350 48 or 36v
Headway 36v pack and 72v pack
Meanwell S350 48 or 36v
Headway 36v pack and 72v pack
Meanwell Mod Power Supply as Lifepo4 Charger
- Thread starter TylerTrinh
- Start date
number1cruncher
1 kW
Tyler,
There are a few ways to mod a MW supply: parallel a resistor to the lowest value resistor in current control divider circuit, snip a shunt or buy a GGoodrum current limiter to append to the MW.
I did the shunt mod. Took less than 5 minutes. However, I'm charging Lipo with mine and it can take whatever the MW throughs at it, since it has a 2C (30Amp in my case) charge capability. I think LiFePO4 requires less than .5C(Headway may be higher), so a typical 10AH battery could only take 5Amps. If charging 1 36V pack, all you would need is 1 s350-36 MW. If charging a 72V pack, buy two and series them, although you would only need to mod one. Good luck!
There are a few ways to mod a MW supply: parallel a resistor to the lowest value resistor in current control divider circuit, snip a shunt or buy a GGoodrum current limiter to append to the MW.
I did the shunt mod. Took less than 5 minutes. However, I'm charging Lipo with mine and it can take whatever the MW throughs at it, since it has a 2C (30Amp in my case) charge capability. I think LiFePO4 requires less than .5C(Headway may be higher), so a typical 10AH battery could only take 5Amps. If charging 1 36V pack, all you would need is 1 s350-36 MW. If charging a 72V pack, buy two and series them, although you would only need to mod one. Good luck!
rkosiorek
100 kW
in the Battery forum there is like a 30 page discussion on modifying switch mode power supplies. the supply being modified by most is the S-350. just use the forum search and you will find it.
rick
rick
mwkeefer
1 MW
Okay - yep there are 30+ pages of notes and misc comments and observations but even I dont have time to read through them all to find what I want so here ya go...
You don't give us the AH or C of your headaway packs but only that they are the 36v and 72v nominal packs... Could you specify how many cells each is in series?
According to a post by YPedal he has been charging at fast rate to 3.7v per cell and then letting them go as far as 3.9v per cell before charge termination... I think this is correct with Headaways... so
[36v Nominal Headaway LiFePo4]
Nominal Voltage: 3.2v
Maximum Voltage: 3.7v per cell
Pack AH: Assuming 20AH?
Assuming these are 12S packs the nominal voltage is 38.4 with a charge maximum of 44.4v - this means you want a Meanwell S-350-48 which you will modify either according to the bullet mods I will provide below or the FULL Thread elsewhere.
Configured Voltage: 44.4 Volts
Charging Current: 7.88 Amps
Now you should perform the SVR1, Thermistor and either R33 or Shunt mod to limit the current... Personally I push my S-350's to 450w output power for 7.3A @ 62.4 which works fine but the closer to 350-380 you get the more reliable.
[72v Nominal Headaway LiFePo4]
This is a 22 or a 24S pack?
I will assume 24S..
Charging Voltage: 88.8v (3.7v per cell, 3.6 is safer for 86.4)
This may be possible with a single S-350-48 though I have never tried to go beyond 63v, the caps are 100v... it will require a bit more current limiting which is a R33 mod or remove all but one shunt.
[Meanwell to Charger Mods]
#1a - Better Adjustment Resolution - Replace variable resistor SVR1 with 10 turn 1K
#1b - Raise Voltage Range (ex 15S) - To raise the voltage range, R25 should be decreased... on our example from 1.95K measured to 1.65k gets me into 15S (63v) charge range. You will also need to either add diodes in series with ZD1 to raise it's 62v limit or replace with proper value if going beyond 62v range extension
#2 - Fan Always On - Replace thermistor nearest output coil with 470-700 ohm resistor, use higher values for higher configured voltages. The fan spins faster at higher voltages so use more resistor to calibrate its output to what you want.
#3 - Remove X shunts or lower R33 to reduce charging current to within 400w @ Max Voltage (charge calibrated voltage).
#4 - Get ARCTIC SILVER thermal paste from either Radio Shack, a Computer Store, etc... be sure to coat the FETs and Flyback Diode before putting the case back together, this will ensure proper heat dissipation - without this, the fan mod is useless.
So those are the bullet points which atleast give you some keywords for searching out the full details of each mod if you need it!
Hope it helps!
-Mike
You don't give us the AH or C of your headaway packs but only that they are the 36v and 72v nominal packs... Could you specify how many cells each is in series?
According to a post by YPedal he has been charging at fast rate to 3.7v per cell and then letting them go as far as 3.9v per cell before charge termination... I think this is correct with Headaways... so
[36v Nominal Headaway LiFePo4]
Nominal Voltage: 3.2v
Maximum Voltage: 3.7v per cell
Pack AH: Assuming 20AH?
Assuming these are 12S packs the nominal voltage is 38.4 with a charge maximum of 44.4v - this means you want a Meanwell S-350-48 which you will modify either according to the bullet mods I will provide below or the FULL Thread elsewhere.
Configured Voltage: 44.4 Volts
Charging Current: 7.88 Amps
Now you should perform the SVR1, Thermistor and either R33 or Shunt mod to limit the current... Personally I push my S-350's to 450w output power for 7.3A @ 62.4 which works fine but the closer to 350-380 you get the more reliable.
[72v Nominal Headaway LiFePo4]
This is a 22 or a 24S pack?
I will assume 24S..
Charging Voltage: 88.8v (3.7v per cell, 3.6 is safer for 86.4)
This may be possible with a single S-350-48 though I have never tried to go beyond 63v, the caps are 100v... it will require a bit more current limiting which is a R33 mod or remove all but one shunt.
[Meanwell to Charger Mods]
#1a - Better Adjustment Resolution - Replace variable resistor SVR1 with 10 turn 1K
#1b - Raise Voltage Range (ex 15S) - To raise the voltage range, R25 should be decreased... on our example from 1.95K measured to 1.65k gets me into 15S (63v) charge range. You will also need to either add diodes in series with ZD1 to raise it's 62v limit or replace with proper value if going beyond 62v range extension
#2 - Fan Always On - Replace thermistor nearest output coil with 470-700 ohm resistor, use higher values for higher configured voltages. The fan spins faster at higher voltages so use more resistor to calibrate its output to what you want.
#3 - Remove X shunts or lower R33 to reduce charging current to within 400w @ Max Voltage (charge calibrated voltage).
#4 - Get ARCTIC SILVER thermal paste from either Radio Shack, a Computer Store, etc... be sure to coat the FETs and Flyback Diode before putting the case back together, this will ensure proper heat dissipation - without this, the fan mod is useless.
So those are the bullet points which atleast give you some keywords for searching out the full details of each mod if you need it!
Hope it helps!
-Mike
TylerTrinh
1 mW
Dude, Mike I private message you with the info. It's all good you are a genius. Now I will have to wrap my mind around the instructions Thanks for your help!! :lol:
mwkeefer
1 MW
Tyler,
Not a genius by any means... thank Tiberious and Jermey Harris for the initial info on modding power supplies for this purpose... then fechter for spotting the current regulation components (for some reason I couldn't figure them out).
All I've really done is take it to a logical conclusion and worked out limits and such...
In response to this request... and dozens more like it, and my own needs for a reference, I began creating a full howto with pictures for converting the typical S-350 models beginning with the 48 (which is why I could answer mods off the hip) and will tag your topic back with the link when I post it.
-Mike
Not a genius by any means... thank Tiberious and Jermey Harris for the initial info on modding power supplies for this purpose... then fechter for spotting the current regulation components (for some reason I couldn't figure them out).
All I've really done is take it to a logical conclusion and worked out limits and such...
In response to this request... and dozens more like it, and my own needs for a reference, I began creating a full howto with pictures for converting the typical S-350 models beginning with the 48 (which is why I could answer mods off the hip) and will tag your topic back with the link when I post it.
-Mike
olaf-lampe
10 kW
Hi Mike!
Nice summary, keeps me from reading 30 pages :lol:
I finally found ZD1 below the transformator.
I have a question to bullet #3:
There is a R37 and a SVR2 not occupied near R33. I hope it is related to an adjustable current limit? Has it been mentioned, how to populate them?
Thanks again for working out the summary. It's worth to become a sticky IMO
-Olaf
Nice summary, keeps me from reading 30 pages :lol:
I finally found ZD1 below the transformator.
I have a question to bullet #3:
There is a R37 and a SVR2 not occupied near R33. I hope it is related to an adjustable current limit? Has it been mentioned, how to populate them?
Thanks again for working out the summary. It's worth to become a sticky IMO
-Olaf
mwkeefer
1 MW
Someone finally posted to the other thread who had the variable current limit (R37/SVR2) populated but I haven't yet had a chance to break it out..
Just modifying R33 will acheive the same goal and you can work a 100-200 ohm 10 turn pot for adjusting the current output.
-Mike
Just modifying R33 will acheive the same goal and you can work a 100-200 ohm 10 turn pot for adjusting the current output.
-Mike
Hi,
I plan to convert a Mean Well SP-100-3.3 (20A) to a single cell LiPOFE4 charger.
My plan is to use an Arduino board as a controller of the charge of each single cell.
I need then a cost effective way to Mod a Mean Well PSU to Lower the current limiting to at least 100% and to be adjustable - if possible - from Ardruino using a digipot.
I understand from previous posts that it is necessary to low down the max current to avoid overheating when charging batteries.
I have 2*8 cells (= 28V) each cell 100AH. I am using them in a sail boat.
I have followed your suggestions for mods of other SP or NES models.
Unfortuenately the board I have seems different from your examples and I cant figure out whats what.
Post a picture of board in hope that you have some suggestions for a mod to manage the current limiter (which it is supposed to have).
I plan to convert a Mean Well SP-100-3.3 (20A) to a single cell LiPOFE4 charger.
My plan is to use an Arduino board as a controller of the charge of each single cell.
I need then a cost effective way to Mod a Mean Well PSU to Lower the current limiting to at least 100% and to be adjustable - if possible - from Ardruino using a digipot.
I understand from previous posts that it is necessary to low down the max current to avoid overheating when charging batteries.
I have 2*8 cells (= 28V) each cell 100AH. I am using them in a sail boat.
I have followed your suggestions for mods of other SP or NES models.
Unfortuenately the board I have seems different from your examples and I cant figure out whats what.
Post a picture of board in hope that you have some suggestions for a mod to manage the current limiter (which it is supposed to have).
Attachments
mwkeefer
1 MW
stenis said:
Look in your own picture, towards the rear (away from the screw terminals), see that IC - TL494 or equivilent, meaning current limiting is nothing more than likely changing or populating a few components on the board. Give a search here, google, etc - TL494 Mods... One thing, I thought LiFePo wanted CVCC but then I could be wrong, likely am - hate that.
In either case, you will need to get the data sheet for the TL494, also look in our postings for which pins should carry the resistor divider network / feedback network for current control and then alter them to work with your digi pot - may I suggest some lipo to test just so you don't overwhelm your LiFePo
_Hope this helps!
-Mike
Thanks!
The IC is a FAN4802. I have found the data sheet.
Now I will try to figure out what on the board.
As I understand it LiFEPO4 charging starts with CC up to 3.65 V. Then it either cuts off or apply some CV with a drop in charging current.
I would be happy if I could do bulk charging with CC and then cut off at 3.65V.
Best regards
Sten-Erik
The IC is a FAN4802. I have found the data sheet.
Now I will try to figure out what on the board.
As I understand it LiFEPO4 charging starts with CC up to 3.65 V. Then it either cuts off or apply some CV with a drop in charging current.
I would be happy if I could do bulk charging with CC and then cut off at 3.65V.
Best regards
Sten-Erik
I have posted the back side of the PCB.
As you can see there is a lot of surface mounted components. This seems to make it more difficult to mod this PSU.
Do you have any suggestions were to start to unwind part of the schema that could contain resistors that regulates the current limiting?
Best regards
Sten-Erik
As you can see there is a lot of surface mounted components. This seems to make it more difficult to mod this PSU.
Do you have any suggestions were to start to unwind part of the schema that could contain resistors that regulates the current limiting?
Best regards
Sten-Erik
Attachments
One last try before I cut the shunts.
In the middle on the back of the PCB I found AP4310 which is a Dual OP Amp and Voltage Reference.
Inputs + to the two OP AMP (INPUT1+/Vka and INPUT2+) have connection via resistors to the shunts.
OP Amp 1 seem to be used for Voltage control and OP AMP 2 for current control according to specs.
Any body have a clue where to look for current limiting?
Best Regards
Sten-Erik
In the middle on the back of the PCB I found AP4310 which is a Dual OP Amp and Voltage Reference.
Inputs + to the two OP AMP (INPUT1+/Vka and INPUT2+) have connection via resistors to the shunts.
OP Amp 1 seem to be used for Voltage control and OP AMP 2 for current control according to specs.
Any body have a clue where to look for current limiting?
Best Regards
Sten-Erik
